Micro Exam 3

Question 1

What are the outcomes of exposure to a microorganism?

Answer 1

• transient colonization
• permanent colonization
• disease

Question 2

colonization

Answer 2

establishment of sit of reproduction of microbes on person without necessarily resulting in tissue invasion or damage

Question 3

infection

Answer 3

growth and multiplication of microbe in or on body of host with or without the production of disease

Question 4

What does normal flora do? (3)

Answer 4

• aid the host
• help development of mucosa immunity
• protect the host from colonization with pathogenic microbes

Question 5

Areas in which normal flora colonize microbes…

Answer 5

• respiratory tract and head
• gastrointestinal tract
• genitourinary system
• skin

Question 6

factors that influence normal flora

Answer 6

• local environment
• diet
• age
• health conditions
• antibiotics

Question 7

pathogenicity

Answer 7

capacity of bacterium to cause disease

Question 8

virulence

Answer 8

measure of pathogenicity of microbe

Question 9

pathogenesis

Answer 9

refers to both the mechanism of infection and the mechanism by which disease develops

Question 10

host defenses

Answer 10

• barriers
• innate immunity
• adaptive immunity

Question 11

opportunistic infections

Answer 11

members of normal flora and cause diseases when they are introduced into unprotected sites

Question 12

carrier

Answer 12

person or animal with asymptomatic infection that can be transmitted to another person or animal

Question 13

zoonosis

Answer 13

infectious diseases transmitted between animals and men

Question 14

characteristics of pathogenic bacteria

Answer 14

• transmissibility
• adherence to host cells
• invasion of host cells and tissue
• evasion of host immune system
• toxigenicity

Question 15

incubation period

Answer 15

length of time required for the bacteria and/ or host response to cause sufficient damage to initiate discomfort or interfere with essential functions

Question 16

mechanisms of bacterial infections

Answer 16

• bacteria-mediated pathogenesis
• host-mediated pathogenesis
• bacterial virulence factors

Question 17

adhesions

Answer 17

• pili
• nonfimbrial adhesions
• allow them to colonize, biofilms

Question 18

invasion of host cells

Answer 18

• tissue damage
• growth byproducts
• tissue-degrading enzymes
• immunopathogenesis

Question 19

toxins

Answer 19

• exotoxins
• enterotoxins
• super antigens
• endotoxin

Question 20

antigenic heterogeneity

Answer 20

• antigenic variation

- phase variation

Question 21

biofilms

Answer 21

can protect bacteria from host defense and antibiotics

Question 22

endotoxin-mediated toxicity

Answer 22

• septicemia (blood toxic)
• symptoms: fever, leukopenia followed by leukocytosis, activation of complement, disseminated intravascular coagulation, decreased peripheral circulation, shock and death

Question 23

superantigen-mediated toxicity

Answer 23

• bind TCR and activate T cells without true antigen present
• autoimmune-like response
• leads to toxic shock syndrome or erythrogenic toxin A or C

Question 24

A toxin

Answer 24

has inhibitory activity against some vital function

Question 25

B toxin

Answer 25

binds to receptor and promotes entry of Atoxin

Question 26

mode of action for A-B toxin

Answer 26

- inhibition of protein synthesis - hypersecretion - inhibition of neurotransmitter release

Question 27

regulation of bacterial virulence factors

Answer 27

- environmental factors - temp - iron availability - osmolarity - pH